1. Field of the Invention
The present invention relates to a photoelectric conversion device including unit cells arranged in a well, where each of the unit cells includes a plurality of photoelectric conversion elements, and to an image pickup apparatus including the photoelectric conversion device.
2. Description of the Related Art
Solid-state image pickup devices manufactured by using complementary metal oxide semiconductor (CMOS) technologies have been shown to be high performance, multifunctional, and low power solid-state image pickup devices. The above-described solid-state image pickup devices are also referred to as CMOS image sensors. Japanese Patent Laid-Open No. 2001-332714 discloses a diagram (FIG. 4) showing a circuit including a contact part used to fix the potential of a well, the contact part being provided for each of a plurality of unit cells, where each unit cell includes two pixels.
When a contact part used to fix the well potential is provided for each of the plurality of unit cells, where each unit cell includes at least two pixels, the symmetry of the layout of conductive lines and/or elements provided in the region of the unit cell becomes irregular, i.e., the layout is non-symmetrical, which may produce a fixed pattern noise. Japanese Patent Laid-Open No. 2001-332714 does not disclose nor suggest an example of a layout of the conductive lines and/or the elements provided in the region of the unit cell. Further, there is no discussion in Japanese Patent Laid-Open No. 2001-332714 of the effect the symmetry of the layout of the conductive lines and/or the elements provided in the region of the unit cell can affect a fixed pattern noise.